Transducer apparatus



Aug. 26, 1969 T. A. SCANLON 3,463,836

TRANSDUCER APPARATUS Filed Sept. 15, 1967 a Sheets-Sheet 1 68 Fl l FIG 2 INVENTOR THOMAS ALBERT SCAN LON BY iii/ 43 3M WW ATTORNEY 6, 1969 T. A. SCANLON 3,463,886

TRANSDUCER APPARATUS Filed Sept. 15, 1967 3 Sheets-Sheet 2 Aug. 26, 1969 T. A. SCANLON TRANSDUCER APPARATUS 5 Sheets-Sheet 3 Filed Sept. 15, 1967 INVENTOR THOMAS ALBERT SCANLON BY JM WT ATTORNEY United States Patent 3,463,886 TRANSDUCER APPARATUS Thomas Albert Scanlon, Barrington, R.I., assignor to P M & E Electronics, Inc., East Providence, R.I., a corporation of Rhode Island Continuation-impart of application Ser. No. 592,519, Nov. 7, 1966. This application Sept. 15, 1967, Ser. No. 668,034

Int. Cl. H04m 1/05; H04r 3/00 U.S. Cl. 179-1 4 Claims ABSTRACT OF THE DISCLOSURE This invention relates to a transducer apparatus and sound tube head set combination, and features an electrical means for opening or closing a selected electrical circuit in the transducer, thereby to control the functioning of the sound tube head set.

This invention is a continuation-in-part of my co-pending patent application Ser. No. 592,519 filed Nov. 7, 1966 for a Transducer Apparatus.

This invention relates to electrical circuit selection means, and more particularly to a sound tube head set which cooperates with a transducer assembly to permit selection of a particular electrical circuit in a plurality of electrical circuits.

In recent years, the provision of entertainment such as motion pictures, television, radio broadcasts, and recorded music for passengers on airplanes and railway trains has become increasingly popular.

In the prior art, passengers were provided with a sound tube head set for insertion into a transducer block. A selector switch was provided to permit the passenger to selectively complete the electrical circuit of a desired sound channel to the input of the transducer unit, whereby the output sound of the selected channel is transmitted to the sound tube head set.

With the advent of a service charge for particular forms of entertainment provided for airplane and railway passengers such as motion picture spactaculars, for example, it has become necessary to isolate the circuit for which a charge is being made, or the pay circuit, from the other or non-pay circuits connected to the input of the transducer block, so that the sound channel of the motion picture circuit, for example, assuming that the motion picture circuit is the pay circuit, could be received only by a passenger who has paid the required fee.

Accordingly, it is an object of this invention to provide an apparatus for use in passenger entertainment systems on airplanes, railways, and the like, which permits a particular electrical circuit to be selected out of a plurality of circuits by a special class of users, namely, those who have been provided with special equipment for making such selection.

It is another object of the present invention to provide an apparatus particularly adapted for use in passenger intertainment systems which permits a pay circuit to be isolated from non-pay circuits, so that only a passenger who has paid to see a particular type of entertainment, having a charge in connection therewith, is permited to be connected to an electrical circuit associated with the pay entertainment.

It is another object of the invention to provide a sound tube head set and cooperating transducer block assembly in which the sound tube head set and the transducer block cooperate to complete the connection of a pay electrical circuit, whereby only a passenger who has paid the required fee and who has been issued a special head set can be connected to the pay circuit.

In achieving these objectives, there is provided a cooperating sound tube head set, specially provided to passengers who have paid a required fee, and a transducer housing or assembly. The plug-in connection between the head set and the transducer assembly includes cooperating electrical contacts on the sound tube head set and on the transducer assembly which complete the electrical connection of a pay circuit to elector switch contacts carried by the transducer assembly, so that the passenger to whom a special head set has been issued can receive the pay circuit as well as all of the non-pay circuits. A passenger who has not paid the fee for the special entertainment would be provided with a sound tube head set also capable of being plugged into the transducer assembly, but without the special contact means on the head set which completes the pay circuits, so that the non-paying passenger can only have his transducer assembly connected to the non-paying circuits.

Further objects and advantages will become apparent from the following description taken in conjunction with the accompanying drawings in which:

FIGURE 1 is a perspective view of a transducer housing and assembly adapted to receive a plug-in connection from a sound tube assembly in accordance with the invention;

FIGURE 2 is a view partially in vertical cross-section and partially in vertical elevation of the transducer housing and assembly of FIGURE 1;

FIGURE 3 is a view in cross-section taken substantially along line 33 of FIGURE 1 showing details of the plugin connection between the sound tube head set and the transducer block;

FIGURE 4 is a view in section along line 4-4 of FIG- URE 1, through the transducer housing assembly;

FIGURE 5 is a schematic wiring diagram showing the circuit connections of a typical passenger entertainment system with which the cooperating head set and trans ducer assembly of the invention might be used; with the cooperating contacts of the transducer housing and of the sound tube head set being shown in disengaged relation;

FIGURE 6 is a view showing the cooperating contacts of the transducer housing and of the sound tube head set in engaged electrical contacting position;

FIGURE 7 is a perspective view of a transducer housing assembly;

FIGURE 8 is a plan view of FIGURE 7;

FIGURE 9 is a vertical cross-sectional view taken on line 99 of FIGURE 8;

FIGURE 10 is a right side elevational view of FIG- URE 7;

FIGURE 11 is a vertical cross-sectional view taken on line 1111 of FIGURE 10; and

FIGURE 12 is a view similar to FIGURE 3 showing the cooperating electrical connection attached to the sound tube head set used in conjunction with the electrical circuit of the transducer housing assembly.

Referring now to the drawings, there is generally indicated at 10 a transducer housing assembly in which are positioned a pair of transducers generally indicated at 12 and 14, respectively. Transducer 12 includes a magnet 16, a voice coil 18 and a diaphragm 20, while transducer 14 includes a magnet 22, a voice coil 24, and 2. diaphragm 26. Transducer housing assembly 10, as shown in FIGURES 1 and 2, is fixed to a casing 10A.

The sound output of the respective transducers 12 and 14 is communicated to a respective one of the sound chambers 28 and 30 with which the plug-in sound tube head set is in communication. Sound chambers 28, 30 terminate at their outer ends in female receptacles 29, 31 which are adapted to receive the male plug-in elements of the sound tube head set, as will be explained hereinafter.

A dual potentiometer including rotatable volume control potentiometers 32 and 34 is positioned within casing 10A. Potentiometers 32 and 34 are mounted on a common shaft which is rotated by means of control knob 36. A selector switch generally indicated at 38, operated by control knob 39, is positioned inside casing 10A and includes three banks or sections of fixed contacts generally indicated at 40, 42, and 44, and cooperating rotatable switch contacts 46, 48, and 50 (see FIGURE which respectively selectively engage the fixed contacts of the respective banks of contacts 40, 42, and 44. The rotatable contacts 46, 48, and 50 may be selectively moved in unison by means of control knob 39 into contact with corresponding fixed contacts of the respective banks of contacts 40, 42 and 44, or into an ofi position associated with each bank of contacts.

The contacts of the contact banks 40, 42, 44 are respectively numbered 1-10, inclusive, in the wiring diagram of FIG. 5 to correspond to the various input channels 1-10, all of which are assumed to be audio circuits. When the control positions such as off or 1-10, inclusive, correspond to the various circuit channels, the rotatable contacts 46, 48, and 50' will respectively be positioned in engagement with the croresponding fixed contacts 1-10 of their associated banks of fixed contacts.

As seen in the wiring diagram of FIGURE 5, one end of transducer winding or voice coil 18 is connected to the movable tap of volume control potentiometer 32. One end of volume control potentiometer 32 is connected by conductor 52 to movable switch contact 46 associated with switch contact bank 40. The opposite side of voice coil 18 is connected across the opposite end of volume control potentiometer 32 at a common juuctlon which is connected to the rotatable contact 44 associated with switch contact bank 42.

One end of transducer or voice coil 24 is connected to the movable tap of volume control potentiometer 34. One end of volume control potentiometer 34 is connected by conductor 54 to the rotatable switch contact 50 associated with contact bank 44. The opposite end of voice coil 24 is connected to the opposite end of the volume control potentiometer 34 and to the common junction of voice coil 18 and volume control potentiometer 32 which is connected to the rotatable contact 48 of switch contact bank 42.

As seen in FIGURE 5, the various sound channels which may be selectively connected to the voice coils of the transducer assembly are connected to the input terminals A-Z, inclusive, A1, B1, and C1. The various input terminals just mentioned are connected to the circuit wiring in the airplane, train, or the like by means of a cable generally indicated at 51. (See FIG. 2.) Thus, in the illustrated embodiment, channel 1 is connected to input terminals A, B, C, D; channel 2 is connected to input terminals E, F; channel 3, which is assumed to be a stereo channel, is connected to input channels G, H, J, K; channel 4 which is also assumed to be a stereo channel, is connected to input terminals L, M, N, P; channel 5 is connected to input terminals R, S; channel 6 is connected to input terminals T, U; channel 7 is connected to input terminals V, W; channel 8 is connected to input terminals X, Y; channel 9 is connected to input terminals Z and A1; and channel 10 is connected to input terminals B1 and Cl.

4 The input terminals just enumerated of the various channels are connected to switch contact banks 40, 42 and 44 in accordance with the particular connections required of the respective channels to the voice coils 18 and 24.

In the case of channel 1, for example, the input terminals A and C are connected in common to terminal 1 of switch contact bank 42, while input terminal B is connected to the input terminal 1 of the switch contact bank 44, and the input terminal D is connected to the terminal 1 of the switch contact bank 40. The connections of channel 1 just described permit separate electrical inputs to voice coils 18 and 24. The two stereo channels 3 and 4 are connected in a similar manner to that just described for channel 1. The remaining channels 2, 5, 6, 7, 8, 9 and 10 are each respectively connected in series across the voice coils 18 and 24, with no connection to the intermediate tap between the two voice coils 18 and 24 as in the case of channels 1, 3 and 4.

All of the audio channels 1-9, inclusive, have their respective conductors connected from the input terminals such as A, B, C, D, etc., directly to the correspondingly numbered terminals on the appropriate switch banks 40, 42 and 44 as required for the particular channels, so that a direct circuit connection is made to the potentiometers and voice coils when the selector switch control knob 39 is rotated to any one of the channels 1-9, inclusive. Thus, a passenger on the airplane or railway may receive the sound input to any of the channels 1-9 in the illustrated embodiment when he plugs the conventional sound tube set into the transducer assembly. However, in accordance with the present invention, the transducer block or assembly and the circuit connections of channel 10 are so arranged that a special sound tube set is required to receive channel 10. It will be understood, of course, that the invention is illustrated as applied to channel 10 merely by way of example, and that the invention could equally well be applied to any of the other channels and, with appropriate modifications could be applied to more than one channel.

Referring now to the schematic diagram of FIGURE 5, it will be noted that channel 10 is provided with two input terminals B1 and C1. Terminal B1 of channel 10 is directly connected to terminal 10 of contact bank 40 by means of conductor 56. It will be noted by reference to FIGURES 5 and 12 of the drawing'that conductor 58 consists of a conductor portion 58A which is connected at one of its ends to the input terminal C1 of the transducer block and at its opposite end to an electrically conductive ring 62 which is fixedly positioned in a countersunk surface at the outer end of the female receptacle 29 communicating with sound chamber 28 on transducer block 10. Conductor portion 58B terminates at one end at terminal 10 of switch contact bank 44, and at its opposite end in a conductive ring 64 which is fixedly positioned in a countersunk surface at the outer end of the female receptacle 31 communicating with sound chamber 30 of transducer block or assembly 10. The part of the transducer assembly constituting at least the portions of sound chambers 28 and 30 contiguous to and defining the female receptacles 29 and 31 is formed of a suitable insulating material, whereby the conductive rings 62 and 64 are maintained in insulated relation to each other.

The sound tube head set or assembly, generally indicated at 66 in the illustrated embodiment, comprises a plug-in member formed of plastic or other suitable insulating material terminating in two male plug-in members 69 and 70. Sound tubes 67 and 68 are connected to the plug-in member of sound tube head set 66. The male 1 plug-in members 69 and 70 are adapted to engage the female receptacles 29 and 31 in which the conducting rings 62 and 64 are located. A U-shaped conducting member or surface 72 is provided in the space lying between the facing walls of the male plug-in elements 69 and 70 so that when the male sound tube plug-in elements 69 and 70 are engaged with the two female receptacles 29 and 31 of the transducer block, as seen in FIGURES 3 and 6, the U-shaped key-like conductive element or surface 72 carried by the sound tube plug-in elements engages the conductive rings 62 and 64 of the transducer block in bridging relation thereto, to thereby close the circuit between the conductor portions 58A and 58B of the schematic diagram of FIGURE 5, and thereby establish an electrical connection from the input terminal C1 of channel directly to the terminal 10 of the contact bank 44. Since conductor 56 is already directly connected from input terminal B1 of the transducer block to terminal 10 of switch contact bank 40, the completion of the connection between conductor portions 58A and 58B as just described completes the connection of terminal C1 to terminal 10 of switch contact bank 44, and thus completes the connection of channel 10 to the appropriate fixed contact banks of the selector switch.

Thus, the passenger who pays for the special entertainment is provided with a sound tube head set having the conductive bridging portion or key 72. When this special sound tube head set is plugged into the receptacles of the transducer assembly, an electrical circuit is completed connecting the pay channel to the appropriate contact bank or banks of the selector switch so that the passenger who has paid for the privilege may have his transducer assembly connected to the input from the pay channel when he turns his channel selector control switch to the pay channel. This same passenger may also receive all of the non-pay channels.

Reference is now made to FIGURES 1, 3, 4 and 8 where a modified construction is illustrated. Transducer housing assembly 10, fabricated from electrically insulated material (as previously stated), is provided with a screw thread 5. A metal screw 6, of electrically conductive material, is rotatively connected to screw thread 5 and contacts conductive rings 62, 64 to provide an electrical bridge between rings 62, 64 to close or complete the circuit therebetween. In that event, the U-shaped mem ber 72 is eliminated from sound tube head set 66 because control knob 39 through conductors 56 and 58 can complete the channel 10 circuit.

If screw 6 is removed the circuit is broken and control knob 39 cannot complete the circuit unless the U-shaped member 72 is provided on the sound tube head set 66 as shown in FIGURE 12.

With reference to FIGURES 3 and 4; the removal of screw 6 provides an air gap or an electrically insulated area in the form of screw thread hole 5. Sound tube head set 66A is illustrated without U-shaped member 72 so that the removal of screw 6 isolates channel 10' of the pay circuit from the non-pay channels.

The passenger who has not paid the appropriate fee for the special entertainment is provided with a sound tube set having a plug-in construction shown in FIGURE 3 of the drawings which does not include the bridging conductive member or key 72, so that the passenger who has not paid the special fee for hearing the pay program is able to receive all of the non-pay channels, such as channels 1-9, but is not able to receive the pay channel, such as channel 10 of FIGURE 5.

It can be seen from the foregoing that there is provided in accordance with this invention a combined plugin arrangement for a sound tube assembly and transducer housing in accordance with which a selected electrical circuit may be completed by plugging in the sound tube assembly to the transducer block, whereby only a passenger who has paid the required fee can complete circuit connections of the pay channel to the transducer assembly. The passenger who has paid for the special pay program may also hear the non-pay programs. On the other hand, the passenger who has not paid to hear the pay program can plug his sound tube head set into the same receptacles of the transducer block, but since his head set is not provided with the special conductive portion 72, or the screw 6 placed in position to bridge rings 62, 64, the head set provided to such passenger does not complete the pay circuit, as previously described.

Attention is directed to FIGURES 3, 9 and 11 for a further description of the valves actuated by male plugs 69 and 70. Female receptacles 29, 31 which are adapted to receive the male plugs 69, 70, respectively, are provided, respectively, with shoulders 90, 91, thereby dividing female receptacles 29, 31 into upper and lower areas.

A plug 92 having a head 93 is slidably mounted in the lower area of female receptacle 29. A band 94 located within the upper area of female receptacle 29 is fastened therein, by means of a drive fit, and abuts shoulder A coil spring is located in the lower area of female receptacle 29 between the bottom of receptacle 29 and head 93. Plug 92 is slidably mounted in band 94 which has an axial bearing for that purpose.

In closed position when male plug 69 is not in female receptacle 29, head 93 engages band 94 under the influence of spring 95 so as to block sound chamber 28 (see FIGURE 11) and prevent sound waves emanating from sound chamber 28. Male plug 69 when manually pressed into female receptacle 29 engages plug 92 forcing head 93 away from band 94, against the tension of spring 95 and thereby permits sound waves to travel from sound chamber 28 to sound tube head set 66A. The valve in female receptacle 31 is constructed and functions in a like manner.

While there has been shown and described particular embodiments of the invention, it will be obvious to those skilled in that art the various changes and modifications that may be made therein without departing from the invention, and therefore, it is aimed to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What is claimed is:

1. In combination, a transducer housing assembly including transducer means intended for installation in a passenger vehicle, a plurality of electrical circuits carrying audio signals, one of said plurality of circuits being a special circuit, a selector switch, means connecting said plurality of electrical circuits to said selector switch for the selection of any one of said plurality of electrical circuits, a sound tube head set, a detachable connection between said head set and said transducer means, whereby said transducer means converts the audio signals carried by any one of said plurality of electrical circuits into sound for passage through said sound tube head set, a pair of spaced apart electrical contacts fixed in said transducer housing, means connecting said special circuit to said spaced apart electrical contacts to interrupt said special circuit, a co-operating electrical contact means removably secured in said transducer housing to provide an electrical connection between said pair of spaced apart electrical contacts to complete the electrical circuit of said special circuit, and whereby removal of said electrical contact means opens the electrical circuit of said special circuit.

2. The structure of claim 1 in which a key is included in the detachable connection element of the head set for bridging said pair of spaced apart electrical contacts to complete said special circuit when said co-operating electrical contact means is removed from said transducer housing.

3. In combination, a transducer housing assembly, intended for installation in a passenger vehicle, having transducer means, and sound chamber means terminating in a pair of female receptacles, a sound tube head set having male elements, respectively, engageable in plug-in relation with said pair of female receptacles and placing said sound tube head set in sound communication with said sound chamber means, a plurality of electrical circuits, one of said plurality of circuits being a special circuit, a selector switch, means connecting said plurality of electrical circuits to said selector switch for the selection of any one of said plurality of electrical circuits to said transducer means, first and second electrical contact means carried by said, respectively, pair of female receptacles and in electrically insulated relation to each other, means connecting said special circuit to said first and second electrical contact means to interrupt said special circuit, and a third electrical contact means removably secured in said transducer housing assembly and adapted to engage said first and second contact means in bridging relation, Whereby to complete the electrical circuit of said special circuit.

4. The combination defined in claim 3, comprising a valve means located in said female receptacle and actuated from closed to open position by means of said male element.

References Cited UNITED STATES PATENTS 2,663,850 12/ 1953 Mellinger et 211. 2,892,889 6/1959 Jones. 3,353,625 11/1967 Scanlon.

OTHER REFERENCES Kissenkotter, German printed application DAS 1,156,441, printed Oct. 31, 1963.

KATHLEEN H. CLAFFY, Primary Examiner C. JIRAUCH, Assistant Examiner 

